18436994 has 4 divisors (see below), whose sum is σ = 27655494. Its totient is φ = 9218496.

The previous prime is 18436987. The next prime is 18437021. The reversal of 18436994 is 49963481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49963481 = 71 ⋅703711.

It can be written as a sum of positive squares in only one way, i.e., 11868025 + 6568969 = 3445^2 + 2563^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4609247 + ... + 4609250.

Almost surely, 2^18436994 is an apocalyptic number.

18436994 is a deficient number, since it is larger than the sum of its proper divisors (9218500).

18436994 is an equidigital number, since it uses as much as digits as its factorization.

18436994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9218499.

The product of its digits is 186624, while the sum is 44.

The square root of 18436994 is about 4293.8320880072. The cubic root of 18436994 is about 264.1780345638.

The spelling of 18436994 in words is "eighteen million, four hundred thirty-six thousand, nine hundred ninety-four".